Many visitors have asked excellent questions about when and why we flood the wetland ponds during the fall and winter at the Preserve. In this video, we’ll inform you on a few of the reasons we flood the ponds and what the timeline looks like from year to year.

  • Every year Preserve staff create a plan for how each pond will be managed.  We adjust that plan frequently based on what grows in each pond and how well the birds use the ponds each year.
  • The Preserve’s wetland ponds get flooded on a rotational basis, beginning with a single pond in late August or early September.  This water supports birds that migrate early, such as shorebirds and some dabbler ducks moving south for the winter.
  • When it is hot, we limit the amount of water that gets released into the ponds. This helps to decrease the risk of diseases, such as avian botulism.
  • We flood ponds very slowly to allow birds to take full advantage of the vegetation and seeds in each ponds.  Flooding them up too quickly to their maximum depth wastes these precious carbohydrate resources and makes the water too deep for the birds to reach the food.
  • We increase the number of ponds that get flooded weekly as the weather cools and as more birds begin to arrive at the Preserve (usually mid to late October).
  • The last few ponds receive water around the middle of December to match the peak number of birds.  This also provides late arrivals access to fresher water.
  • We manage water level depths for all species of waterfowl and waterbirds, so some ponds (or areas within ponds) will be shallow mudflats for shorebirds, while other areas will be deep for diving ducks.
  • In the spring, we drain several ponds very slowly so the birds can take advantage of the aquatic invertebrates that get concentrated into the remaining available water.  This is a huge protein source for birds about to migrate north for the breeding season.
  • In the summer, we disk, mow, and irrigate ponds to promote desirable vegetation, including three of the most important plants for waterfowl: watergrass, smartweed, and swamp timothy. 
Flooding the Preserve’s Managed Wetlands